Each year approximately 8 million surgical procedures are performed and thousand of lives are lost resulting from complications caused by tissue or organ failure. Despite the significant advances made in the arena of whole organ transplantation, there remain many problems such as limited number of donor organs and foreign tissue rejection. Engineered tissues offer many advantages - the most notable being that only cells and a natural or synthetic scaffold are required for regeneration. The use of synthetic polymer matrices is preferred over natural materials, such as collagen, since batch variation is better controlled, engineering properties are superior, and ease of fabrication into many shapes and sizes. The main limitations in developing this technology are finding suitable materials that can be universally utilized in the body and methods of fabricating appropriate porous structures. We have elected to investigate a family of tyrosine polycarbonates based on their favorable tissue compatibility and engineering properties. We intend to develop a CO2 based process to fabricate highly porous open- pore constructs suitable for use in tissue engineering applications. Employing a CO2 blown process to generate porous morphologies eliminates use of organic solvents, minimizes the risk of residual contaminants, and is environmentally benign. PROPOSED COMMERCIAL APPLICATIONS: There are approximately 8 million surgical procedures annually to address tissue losses and organ failures, estimated to be $800 billion in annual health care costs in the United States. The shortage of organs and tissues for transplantation remains, and it is critical that alternatives be developed. The ability to eliminate the high costs associated with transplantation and related issues to the health care system by development of an off-the-shelf alternative, as well as a reduction in maintenance treatments and hospital stays prior to organ and tissue availability, has the potential of improving the quality of life for patients in a shorter time frame and alleviation of related societal costs such as lost work time and availability of medical resources.